JPS63202628A - Production of thermosetting resin - Google Patents

Abstract

PURPOSE:To obtain a thermosetting resin having excellent heat resistance, chemical resistance, mechanical characteristics, and rapidly curing properties, without evolving volatile components and requiring a solvent, by condensing oxazoline with a specific polyol compound in the presence of a compound catalyst. CONSTITUTION:(A) An oxazoline derivative shown by the formula (n is 2-4; R is n-valent aliphatic group, etc.; Ra-Rd are H or <=3C aliphatic group) is blended with (B) a polyol compound (e.g. phenolic novolak, etc.) obtained by condensing a phenol with an aldehyde in an amount to give preferably 10-120% OH equivalent of the component B based on equivalent of the component A. Then any of a protonic acid (e.g. methane-sulfonic acid, etc.) having <=2.5 PKa, a protonic acid ester (e.g. methyl benzenesulfonate, etc.) having <=1.0 PKa, Lewis acid (complex), an alkyl halide and iodine is added as a catalyst to the blend and reaction is carried out under heating to give the aimed resin.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for producing a thermosetting resin, and more specifically, a thermosetting resin having excellent heat resistance, chemical resistance, R mechanical properties, etc. The present invention relates to a method for producing a fast-curing and excellent moldability.

<Prior Art> In recent years, with the advancement of technology, there has been a demand for resins with excellent heat resistance, mechanical properties, and moldability. Among these resins, reaction-molding resins using reactive monomers or oligomers, that is, resins in which molding and polymerization are simultaneously performed using low-viscosity raw materials, are attracting particular attention. Such resins include polyurethane resin and polyurea resin.

Nylon resins, epoxy resins, unsaturated polyester resins, etc. are known, and some are commercialized.

However, each of these resins has its advantages and disadvantages.
For example, polyurethane resins have low heat resistance, and unsaturated polyester resins have drawbacks such as a long reaction time, that is, molding, and therefore cannot necessarily be said to have sufficient performance and moldability.

Furthermore, the reaction between oxazoline and carboxylic acid is well known, and thermosetting resins using it have also been proposed (Japanese Patent Publication No. 59-226021). There are no known resins, and in fact, there is almost no reaction without a catalyst.

<Object of the Invention> As a result of intensive research to develop a new thermosetting resin, the present inventors discovered that oxazoline and a specific polyol compound,
In other words, the reaction between phenols and polyol compounds obtained by condensation of aldehydes occurs in the presence of a specific catalyst.
It progresses extremely quickly and becomes a tough thermosetting resin, and because this resin releases volatile components during the reaction process and does not require a solvent, it is extremely suitable for reaction molding, such as a two-component mixture type reaction molding. It has been discovered that it can be usefully manufactured, and the present invention has been achieved.

Therefore, an object of the present invention is to provide a method for producing a thermosetting resin having excellent heat resistance, chemical resistance, mechanical properties, etc., which is fast-curing and has excellent moldability.

<Structure/Effects of the Invention> According to the present invention, an object of the present invention is to provide an oxazoline derivative represented by the following formula (I) (which may have different formulas) and a phenol and an aldehyde. The resulting polyol compound is heated in the presence of a catalyst selected from protic acids with a PKa of 2.5 or less, protic acid esters with P and a of 1.0 or less, Lewis acids and their complexes, alkyl halides, and iodine. This is achieved by a method for producing a thermosetting resin characterized by a reaction.

The oxazoline derivative used in the present invention, which will be described in detail below, is a compound represented by the following formula (I); 2 is preferred.

R represents an n-valent Frm aliphatic, alicyclic, or aromatic hydrocarbon group, and when n=2, R may be a direct bond. Specifically, R is n=2 In the case of ethylene 1 trimethylene, propylene, tetramethylene, hexamethylene, neobendylene.

Aliphatic with 10 or less carbon atoms, alicyclic group with 10 or less carbon atoms, 1 carbon number
Two or less aromatic hydrocarbon groups are preferred.

Ra, Rb, RC and Rd are hydrogen atoms, carbon number 3
The following aliphatic and aromatic hydrocarbon groups having 7 or less carbon atoms are shown, and these may be the same or different. Carbon number 3
Specific examples of the following aliphatic hydrocarbon groups include methyl and ethyl, and examples of aromatic hydrocarbon groups having 7 or less carbon atoms include phenyl and tolyl. Ra, Rb
, Rc and Rd are preferably all hydrogen atoms, or any one of them is methyl and the others are hydrogen atoms, and it is particularly preferable that all of them are hydrogen atoms.

Specifically, the oxazoline derivatives used in the present invention include 2,2°-bis(2-oxazoline), 2.
2'-Ethylenebis(2-oxazoline).

2.2°-tetramethylenebis(2-oxazoline).

2.2°-hexamethylenebis(2-oxazoline).

2.2°-octamethylenebis(2-oxazoline).

2.2°-1,4-cyclohexylenebis(2-oxazoline), 2,2°-bis(4-methyl-2-oxazoline), 2,2°-bis(5-methyl-2-oxazoline), 2,2°-m-phenylenebis(2
-oxacillin), 2,2°-p-phenylenebis(2-oxazoline), 2,2'-m-phenylenebis(4-methyl-2-oxazoline), 2,2°-m
-phenylenebis(5-methyl-2-oxazoline),
2゜2゜-p-phenylenebis(4-methyl-2-oxazoline), 2,2゜-p-phenylenebis(5-
Examples include methyl-2-oxazoline), 1,3.5-tris(2-oxazolinyl-2)benzene, and the like. Among these, 2.2°-bis(2-oxacillin), 2,2°-tetramethylenebis(2-oxazoline), 2,2°-m-phenylenebis(2
-oxacin), 2,2'-p-phenylenebis(
2-oxazoline) are preferred, and these are used singly or as a mixture of two or more.

The oxazoline derivative used in the present invention can also be used by replacing a part of it with a monooxazoline compound represented by the following formula (I[). Specifically, the monooxazoline compound represented by (If) includes 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-propenyl-
2-oxazoline.

2-phenyl-2-oxazoline, 2-tolyl-2-oxazoline, 2,5-dimethyl-2-oxazoline, 2
, 4-dimethyl-2-oxazoline, 2-phenyl-4
-Methyl-2-oxazoline, 2-phenyl-5-methyl-2-oxazoline, and the like. Among these, 2-phenyl-2-oxazoline and 2-tolyl-2-oxazoline are preferable, and the proportion of the monooxazoline compound used is preferably 30 mol% or less with respect to the polyoxazoline compound represented by formula (I), It is more preferably 25 mol% or less, particularly preferably 20 mol% or less.

The polyol compound reacted with the oxazoline derivative in the present invention is a polyol compound obtained by condensation of phenols and aldehydes. This phenol label refers to aromatic hydroxyl group-containing compounds, specifically phenol, cresol, hydroquinone, resorcinol, xylenol, α-naphthol, β-naphthol,
Examples include dihydroxynaphthalene. Among these, phenol is preferred. Examples of aldehydes include formaldehyde, acetaldehyde, glyoxal, glutaraldehyde, benzaldehyde, p-hydroxybenzaldehyde, and m-hydroxybenzaldehyde.

Examples include terephthalaldehyde.

Among these, formaldehyde is preferred.

The condensation of phenols and aldehydes can be carried out by a known method. For example, a polyol compound can be obtained by a conventionally known production method in which phenols and aldehydes are dehydrated and condensed in the presence of an acid or alkali catalyst. . In addition, it is industrially produced as a polyol compound,
Various commercially available phenol resins can also be used as they are. Among these, phenol novolak is particularly preferred as the polyol compound.

The usage ratio of the oxazoline derivative and the polyol compound is as follows:
The ratio of H equivalent is preferably 10 to 120%, and 30 to 120%.
A ratio of 110% is more preferred, and a ratio of 50 to 100% is particularly preferred.

The thermosetting resin of the present invention combines the above-mentioned oxazoline derivative and the above-mentioned polyol compound into a protonic acid having a PKa of 2.5 or less, a protonic acid ester having a Pka of 1.0 or less,
It is obtained by a heating reaction in the presence of a catalyst selected from Lewis acids and their complexes, alkyl halides, and iodine.

Here, PKa is the value in an aqueous solution, and when there are two or more dissociable protons, it represents the value for the first proton.

Examples of the above-mentioned catalyst include sulfonic acids, inorganic protonic acids, etc. as protonic acids having a Pka of 2.5 or less.
Examples of the sulfonic acids include methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, etc., and examples of the inorganic protonic acids include sulfuric acid, phosphoric acid, stannous acid, phosphinic acid, phosphonic acid, and perchloric acid. Examples include acids. Examples of protonic acid esters having a PKa of 1.0 or less include methyl benzenesulfonate, ethyl benzenesulfonate, methyl P-toluenesulfonate,
Examples include sulfonic acid esters such as ethyl p-toluenesulfonate, and inorganic protonic acid esters such as dimethyl sulfate. Lewis acids and their complexes include:
Examples include titanium tetrachloride, tin tetrachloride, zinc chloride, aluminum chloride, trifluoroborane, trifluoroborane ether complex, and the like. As an alkyl halide,
For example, methyl iodide, ethyl iodide, propyl iodide.

Examples include butyl iodide, benzyl iodide, benzyl bromide, and the like. These catalysts can be used alone or in combination of two or more. There is no particular restriction on the amount of these catalysts to be used, and it is preferably 0.0000% relative to the oxazoline derivative used.
The amount is about 0.01 to 20 mol%, more preferably 0.05 to 15 mol%, particularly preferably about 0.1 to 10 mol%.

As a reaction method, for example, oxazoline derivatives.

A method in which a solid and/or liquid polyol compound and a catalyst are physically mixed homogeneously, the mixture is melted by heating, the mixture is filled into a mold having a desired shape, and the mixture is heated and reacted in the mold. method), a method in which the oxazoline derivative and the polyol compound are melted separately, mixed using a mixing means such as a mixing head, and then directly injected into a mold of the desired shape preheated to the reaction temperature to react (two-liquid mixing method). law), etc. In the case of two-component mixing method,
It is preferable that the catalyst is contained in the polyol compound or a component mainly composed of the polyol compound.

The reaction temperature varies depending on the type of oxazoline derivative, polyol compound and catalyst used, their usage ratio, etc., but is preferably 60 to 340°C, more preferably 70 to 340°C.
00°C, particularly preferably about 80 to 260°C.

The reaction time may be sufficient as long as it is sufficient to harden the target resin, and this time varies depending on the type of raw materials used, the ratio used, the reaction temperature, etc., but is preferably 1.
The time is about 0 seconds to 60 minutes, more preferably 20 seconds to 30 minutes, particularly preferably about 30 seconds to 15 minutes.

The reaction can be carried out at normal pressure to increased pressure, but at this time nitrogen is used to prevent water in the atmosphere and oxidative deterioration of the resin.

It is preferable to carry out under an inert gas atmosphere such as argon.

Note that the thermosetting resin of the present invention may contain carbon fibers,
Reinforcing materials such as glass fiber, various fillers.

Additives such as fillers, pigment 1 colorants, oxidation stabilizers, ultraviolet absorbers, and keying agents may be blended as appropriate.

Examples> Hereinafter, the present invention will be described in detail with reference to Examples, but the Examples are for illustrative purposes and the present invention is not limited thereto.

In the examples, "part" means "part by weight", and the heat distortion temperature was measured using a DMA (dynamic thermomechanical property measuring device) at a heating rate of 10° C./min.

Examples 1-4 2.2'-m-phenylenebis(2-oxacillin) 1
00 parts and the amounts shown in Table 1 of a phenol novolac having an average molecular weight of about 600 and a catalyst in a glass reactor,
The reaction mixture, which was purged with nitrogen and heated to the temperature shown in Table 1, generated heat to reach the maximum temperature after the time shown in Table 1 and was cured. All of the obtained resins were transparent yellow and tough, and had excellent solvent resistance without dissolving or swelling even in trichlene, acetone, xylene, or ethyl acetate.

Furthermore, Table 1 shows the heat distortion temperatures of the obtained resins, and it can be seen that all of them have excellent heat resistance.

Table 1 Example 5 2.2°-m-phenylenebis(2-oxazoline) 1
00 parts, phenol novolak (Sumilight Resin PR
-50731, manufactured by Sumitomo Durez Co., Ltd.) and 3 parts of p-toluenesulfonic acid were charged into a reaction vessel, mixed well, and then heated to 180°C under nitrogen atmosphere.
After a few seconds, it generated heat to 240°C and was cured.

The obtained resin is light orange and transparent, has no bubbles, and is strong.
The heat distortion temperature was 166°C.

Claims (1)

[Claims] The following formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (I) [In the formula, n represents an integer of 2 to 4, R represents an n-valent aliphatic group,
Indicates an alicyclic or aromatic hydrocarbon group. However, when n=2, R may be a direct bond. Ra, Rb, Rc and Rd represent a hydrogen atom, an aliphatic hydrocarbon group having 3 or less carbon atoms, and an aromatic hydrocarbon group having 7 or less carbon atoms, and these may be the same or different. ] The polyol compound obtained by condensation of the oxazoline derivative represented by phenol and aldehyde is combined with a protonic acid having a PKa of 2.5 or less, a protonic acid ester having a PKa of 1.0 or less, a Lewis acid and its complex, A method for producing a thermosetting resin, which comprises carrying out a heating reaction in the presence of a catalyst selected from an alkyl halide and iodine.